Trial of Lucy Letby

David Davis Excerpts

Wednesday 8th January 2025 Commons Chamber

[David Davis (Goole and Pocklington) (Con)]

I am not in the habit of issuing trigger warnings, but I must warn the House that this speech will cover deeply distressing events. I will discuss infant deaths, failures in care and allegations of a grave miscarriage of justice.

Lucy Letby was convicted of murdering seven infants and attempting to murder seven more. She received multiple concurrent full-life sentences. The case horrified the nation. It seemed clear: a nurse had turned into a serial killer. I initially accepted the tabloid characterisation of Letby as an evil monster, but then I was approached by many experts, including leading statisticians, neonatal specialists, forensic scientists, legal experts, and those who had served at the Chester hospital and are afraid to come forward. The experts included a past president of the Royal Statistical Society and a past president of the Royal College of Paediatrics and Child Health—people who were more knowledgeable than the purported experts whose evidence convicted Lucy Letby. They were all concerned by what they perceived as the false analyses and diagnoses used to persuade a lay jury to convict Letby.

Sadly, none of us is a stranger to miscarriages of justice; there have simply been too many. The Birmingham Six, the Guildford Four and the Stockwell Six are the famous ones, but the Exeter University miscarriage database lists nearly 500 people who have been wrongfully imprisoned. Astonishingly, wrong forensic evidence is responsible for 81 cases leading to over 500 years of unjust imprisonment. Many of those cases involve caregivers convicted by medical expert testimony asserting deliberate harm where causes of death were in fact natural. Those people were all exonerated, but those who doubted their guilt were initially met with the same fierce public pushback that now faces those who question Letby’s guilt.

So what has happened here? The Countess of Chester hospital neonatal unit suffered a sharp increase in deaths, from a typical two to four a year to 17 in one 13-month period. When hospital senior management became aware of the elevated mortality in June 2016, they were alarmed and commissioned some investigations. The most notable was carried out in November 2016 by the Royal College of Paediatrics and Child Health, whose report noted many failings on the unit, all of which—at least in part, if not in total—could have been the cause of the deaths. The report highlighted inadequate staffing levels, delayed escalation of concerns to tertiary units and

“disconnection between the neonatal leadership and the trust’s government and risk management processes.”

In essence, because of a mixture of inadequate resources and poor medical management, the hospital was not capable of keeping those very fragile babies alive. That fact was recognised by the hospital when the neonatal unit was downgraded in July 2016 and stopped taking babies of less than 32 weeks’ gestation. The report, offering completely different reasons for the deaths, was never shown to the jury.

Some consultants had attempted to blame Letby for the deaths. A redacted section of the report states:

“The consultants explained that their allegation was based on Nurse L being on shift on each occasion an infant died (although not necessarily caring for the infant) combined with ‘gut feeling’. There was no other evidence or history to link Nurse L to the deaths, and her colleagues had expressed no concerns about her practice.”

[Andrew Cooper (Mid Cheshire) (Lab)]

Will the right hon. Gentleman give way?

[David Davis]

No, I am afraid I will not—I am short of time.

Again, that section of the report was never shown to the jury. Those consultants then persuaded management to call the police in April 2017. There was no hard evidence against Letby. Nobody saw her do anything untoward. The doctors’ “gut feeling” was based on a coincidence: she was on shift for a number of the deaths, but—and this is important—far from all of them. The case was built on a poor understanding of probabilities that was to translate later into an influential but spectacularly flawed piece of evidence.

Around that time, the hospital was struggling with another problem—and possibly a more sensible explanation for this sudden increase in deaths. Leaked reports show that the hospital, and specifically the neonatal unit, battled a Pseudomonas aeruginosa infection for months. That antibiotic-resistant bug posed a serious risk to the babies. The child mortality rate for Pseudomonas aeruginosa ranges from 14.5% to 50%, and stands at over 55% for infants of extremely low birth weight, such as those in this case. It is hard to see how we can eliminate that as the cause of death or collapse for at least some of those babies. Again, the jury never knew about that contamination.

From the start of the case, Cheshire police picked up on the doctors’ statistical arguments supposedly pointing to Letby. In April 2018, an officer on the investigation approached a leading statistician, Professor Jane Hutton, and asked her to put a figure on the likelihood of a nurse being on duty “during all the deaths/collapses” in the unit. Of course, that is a false proposition, as Letby was not on duty for anything like all the deaths—as we will see later—but that was glossed over at the trial. Notwithstanding that, Professor Hutton informed the police that any proper statistical inquiry should not concentrate on one staff member from the outset. Instead, it would require full, proper research into all possible explanations for any increase in babies collapsing, including their medical conditions and prematurity, as well as the broader performance of the unit. One would think that would be common sense.

Cheshire police then signed a consultancy agreement with Professor Hutton, but in 2021, after Letby had been charged, the police wrote an email to Professor Hutton, stating:

“We have had a further meeting this afternoon where we have informed the prosecutors that we were looking at the validity of statistical evidence again in the case… The prosecutor…has instructed us not to pursue this avenue any further at present.”

This appears to be in direct contravention of part 3.3 of the code for Crown prosecutors, which states:

“Prosecutors cannot direct the police or other investigators.”

Again, the jury was never informed of Professor Hutton’s explicit advice to the police that their statistical approach was flawed. This matters enormously, because the most powerfully influential piece of evidence in the case was the prosecution King’s counsel showing a table with Letby listed as the only nurse on duty for all of the alleged murders and inflicted injuries. Professor Hutton, who has reviewed the case extensively, believes that deeply flawed statistical evidence was used, and has said that the statistical errors are “similar to those…in the Sally Clark case but worse.” Sally Clark was convicted and then acquitted of the murder of her two sons based on flawed statistical evidence.

In May 2017, Dewi Evans, a retired doctor who runs a business that provides highly paid medical “expert evidence” in court cases, approached the National Crime Agency to volunteer his services. Evans’s opinion that Letby injected air either into the babies’ veins, causing air embolism, or down the nasogastric tube into the stomach, stopping the babies’ breathing, was one of the foundations—indeed, probably the major foundation—of the prosecution case. This supposed evidence is hugely controversial. Three months into the murder trial, Letby’s defence team applied for evidence from Dewi Evans to be excluded due to an adverse judgment from a judge in a previous case, who said that a report by Dr Evans was “worthless” and

“makes no effort to provide a balanced opinion”.

In an extraordinary and—as far as I can see—unprecedented intervention, that very judge, Lord Justice Jackson, actually wrote to the trial judge with his judgment on Dr Evans attached, clearly indicating how unsuitable Evans was as an expert witness.

Evans’s assertion of murder by air embolism was entirely based on a research paper from 1989, and its relevance in these cases has been robustly challenged by the actual author of that paper. Evans changed his opinion on several key issues during the trial, and is now accused by Letby’s lawyer of changing his opinion again since the end of the appeal process. Evans disputes this, but if Members are interested, I suggest that they compare his evidence recorded in the trial transcript of 1 November 2022 with his signed statement to Channel 5 on 3 August 2024 and decide for themselves. It is also the case that Evans has submitted a new report to the police. What is extraordinary, however, is that the Crown Prosecution Service has refused to provide a copy of that report to Letby’s current defence counsel.

Questions have also been raised about the second expert witness for the prosecution, Dr Sandie Bohin. Eight families are currently filing formal complaints against her over their children’s care, which are being considered by the General Medical Council.

That brings us to the actual cases and causes of the deaths. Two expert neonatologists—consultant working neonatologists—are working through the cases to establish the actual causes of the babies’ deterioration and deaths. They are doing so thoroughly, so this is taking time. So far, they have completed two detailed case reviews for babies O and C. There are five more that will be completed in the near future.

In the case of Baby O, the prosecution claimed the baby was attacked with blunt trauma to the liver and had air injected into the nasogastric tube. The case notes tell a different story, showing how the doctors used excessive ventilation pressure during resuscitation, which overinflated the baby’s lungs and prevented blood from flowing back to the lungs. This caused the baby to desaturate his blood oxygen level repeatedly. The medical team responded by increasing the pressures even more, initiating a downward spiral in the baby’s condition. The overinflation of the baby’s lungs forced the diaphragm downwards, pushing the liver into the baby’s abdominal cavity.

The consultant in charge took a decision to insert a needle into the abdomen to release what they thought was gas pressure in the abdomen. However, this was wrongly inserted into the right side of the baby’s abdomen. As a result of this error, the needle penetrated the liver, causing serious internal bleeding. This was undoubtedly a significant contributory factor in the baby’s death, if not the outright cause. The report states that the

“deterioration was predictable, and his death was avoidable and resulted from suboptimal care.”

The author of that sub-optimal care, the doctor who inserted the needle into the liver, was one of the principal accusers of Lucy Letby at the trial. This directly contradicts the prosecution’s portrayal of events. The trauma to the liver was caused by a serious error by one of the consultants who led the accusations against Letby. The experts also stated that there was no air in the gut in excess of what would be expected for a baby in these circumstances. None of this was made clear to the jury. The prosecution’s evidence was again predicated on Dewi Evans’s diagnosis, which in this specific case alone changed multiple times.

In the case of Baby C, the prosecution claimed this was a healthy baby killed by air being injected into his stomach. The case notes for Baby C demonstrate that this baby was actually profoundly unwell before birth. The baby suffered from severe foetal growth restriction. This meant the baby had to be delivered by caesarean section at an extraordinarily low birth weight, even for that gestation, of 800 grams or about 1.75 lb. Within an hour of birth, he developed respiratory distress. To treat the respiratory problems, they tried to deliver surfactant, a mixture that helps babies’ lungs to expand better—open up—down an endotracheal tube.

The case notes, however, show that the doctor pushed the tube too far in, pushing it into one lung, meaning that the other lung was left collapsed. In the days after the baby’s birth, he showed several signs of abdominal obstruction, including the vomiting of bile, and he never opened his bowels since birth, which the doctor in charge did not recognise or diagnose. The report concludes by stating that this baby died of natural causes compounded by sub-optimal medical care. This again directly contradicts the prosecution’s narrative of deliberate harm. Dewi Evans’s diagnosis claimed the baby had air injected into the stomach, so he could no longer breathe. This was predicated on an X-ray showing an unusual amount of air on the stomach. It has become clear that Letby was not even at the hospital when the X-ray was taken, nor had she been at any point till then since Baby C’s birth two days earlier. While the baby died from natural causes, there is evidence of sub-optimal care, including

“the administration of surfactant and the lack of recognition and appropriate management of signs of abdominal obstruction”.

Again, the doctor responsible for these errors was another one of those who made accusations against Lucy Letby and, again, none of this was made clear to the jury.

There is a great deal of evidence demonstrating that there are much more likely alternative causes of these tragic deaths than those put up by the prosecuting team. The most likely is that the hospital’s neonatal unit was not up to caring for these fragile children, in terms of either resource or skill, and this shortcoming might have been compounded by other factors such as the Pseudomonas infection.

[Jesse Norman (Hereford and South Herefordshire) (Con)]

My right hon. Friend will be aware that there is a family connection with my constituency of Hereford and South Herefordshire. What he says is deeply troubling and distressing on so many different levels, and I would like to ask whether his conclusion is that there is some case in justice to consider this an unsafe verdict.

[David Davis]

There is a case in justice for a retrial in my view, but there is a problem—I would say it is a technical problem. One of the problems we face is that much of the evidence was available at the time. What I have described is an expert analysis of the case notes that were there at the time, but it was simply not presented to the jury. That means that the Court of Appeal can dismiss it, basically saying that the defence should have presented it at the initial trial. It is in essence saying, “If your defence team weren’t good enough to present this evidence, hard luck, you stay banged up for life.” That may be judicially convenient, but it is not justice. This has been a historic problem in Britain, delaying the resolution of a number of miscarriage of justice cases.

Secondly, the so-called expert evidence in this case largely amounted to putting together theories suiting the prosecution case, from the bogus statistical arguments through to the wrong diagnoses I have just detailed. Again, this problem is not new. In 2011 the Law Commission made a number of recommendations precisely on the handling of expert evidence. There is even a section in it entitled, “Inferring murder from unexplained infant deaths.” Those recommendations have not made it into law nearly 15 years later, and it is past time that was put right. Perhaps most worrying of all in this case is that it is just the latest example, more than a decade after the Mid Staffs scandal, of the national health service’s inability to analyse its own failings. This matters because until we learn these lessons, there will continue to be unnecessary deaths in hospitals up and down the country.

My central argument today, which comes back to what my right hon. Friend asked me, is about what to do about a trial which, in my view, is a clear miscarriage of justice by a judicial system that could not manage admittedly difficult statistical and medical scientific evidence. The only body available to correct this today is the Criminal Cases Review Commission. In my view, it should look at all the new diagnoses when they come out, and if necessary consult the leading neonatal and statistical authorities in the land—the most expert people, who are much more equipped to give proper assessment than the experts who were employed by the police at the time. As a result, in my view it should order a retrial, and it should do it quickly.

This is significant because the CCRC has recently been criticised—Members may have read about it in the Andrew Malkinson case, where there was effectively a 17-year delay in releasing him from prison. DNA evidence proving him innocent of the rape he was convicted of was known four years after his conviction, yet it took a further 13 years to correct it. That cannot happen again. We cannot repeat that. If, as I believe it will, a retrial clears Lucy Letby, she should be released in her thirties, not in her fifties.